Vehicle seat

Abstract

The invention relates to a vehicle seat comprising a base portion for attachment in a vehicle; a seat bottom part, with a top side and an underside, which seat bottom part is attached to the base portion; a waist belt, which extends between the seat bottom part's sides. At least one hinge mechanism that is adjustable between a first and a second position is arranged at the base portion. The waist belt is attached to the hinge mechanism, so that the waist belts position in relation to the seat bottom part changes when one on the seat bottom part acting force reaches a predetermined value, which force leads the hinge mechanism from the first to the second position.

The invention claimed is: 
     
       1. Vehicle seat comprising:
 a base portion for attachment in a vehicle; 
 a seat bottom part, with a top side and an underside, which seat bottom part is attached to the base portion, wherein the top side of the seat bottom part comprises a resilient support surface, which is arranged at and supported by an at least partially around a support surface surrounding frame; 
 a waist belt extending between the seat bottom part's sides, and 
 at least one hinge mechanism, that is adjustable between a first position and a second position, arranged at the base portion, 
 wherein the waist belt is attached to the hinge mechanism, 
 an actuator extends substantially parallel with the seat bottom part's underside and is attached to the at least one hinge mechanism, so that the actuator moves the hinge mechanism from the first position to the second position, and 
 a position of the waist belt in relation to the seat bottom part changes when a force acting on the seat bottom part reaches a predetermined value so as to make the actuator move the hinge mechanism from the first position to the second position, the force being a downwards acting force generated by mass inertia of a person sitting in the seat when the seat moves at a high speed upwards. 
 
     
     
       2. Seat according to  claim 1 , characterized in that the actuator is a belt, extending along the seat bottom part's underside and configured to receive the force of the predetermined value. 
     
     
       3. Seat according to  claim 1 , characterized in that the hinge mechanism comprises a locking lug which interacts with pawls arranged on the hinge mechanism, such that the locking lug engages with a first pawl when the hinge mechanism is in the first position and that the locking lug engages a second pawl when the hinge mechanism is lead to the second position. 
     
     
       4. Seat according to  claim 3 , characterized in that the seat bottom part is hingeably attached to the base portion, so that the seat bottom part can be raised to a substantially vertical position in which the locking lug engages with a third pawl on the hinge mechanism. 
     
     
       5. Seat according to  claim 4 , characterized in that a pull down hook is arranged at the at least one hinge mechanism, which pull down hook interacts with the seat bottom part, so that the pull down hook rotates the hinge mechanism to the first position when the seat bottom part is lowered from the substantially vertical position to a substantially horizontal position. 
     
     
       6. Seat according to  claim 1 , characterized in that the hinge mechanism is rotatable between the first and the second position. 
     
     
       7. Seat according to any of  claim 1 , characterized in that the hinge mechanism is substantially linearly displaceable between the first and second position. 
     
     
       8. Seat according to  claim 1 , characterized in that a hinge mechanism is arranged on each side of the seat and that the waist belt is extending between the hinge mechanisms. 
     
     
       9. Seat according to  claim 1 , characterized in that a backrest is arranged at the base portion, which backrest is supported by cords attached to the vehicle. 
     
     
       10. Seat according to  claim 1 , characterized in that a shoulder belt is at a first end attached to the waist belt and with a second end attached to the vehicle.